Iodine and hypothyroidism in neonates with congenital heart disease.
OBJECTIVE
To evaluate the influence of the intravenous injection of iodine during cardiac catheterisation, and of topical iodine antiseptics during surgical procedures, on thyroid function in full term neonates.


METHODS
Twenty one full term infants with major cardiac anomalies who survived for more than a month were studied. Thyroxine and thyrotropin concentrations were measured (by radioimmunoassay) before each procedure, 24 hours after the procedure, and every week thereafter until the age of 1 month or until normal. Thyroxine values less than 64.4 nmol/l were considered low, while thyrotropin values greater than 30 mU/l were considered high.


RESULTS
Thyroid function tests before iodine exposure were within normal limits in all infants. Following catheterisation or surgery six infants had raised thyrotropin concentrations; three had low thyroxine concentrations. Two of those infants were treated with L-thyroxine.


CONCLUSIONS
Iodine exposure during cardiac catheterisation or surgery may induce transient hypothyroidism in term infants.
Linder
N
N
Department of Neonatology, Sheba Medical Center, Sackler School of Medicine, Tel Aviv University, Israel.
Sela
B
B
German
B
B
Davidovitch
N
N
Kuint
J
J
Hegesh
J
J
Lubin
D
D
Sack
J
J
D000891:Anti-Infective Agents, Local / Q000009:adverse effects; D006328:Cardiac Catheterization; D003287:Contrast Media / Q000009:adverse effects; D006330:Heart Defects, Congenital / Q000628:therapy*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000139:chemically induced*; D007231:Infant, Newborn; D007455:Iodine / Q000008:administration & dosage / Q000009:adverse effects*; D011206:Povidone-Iodine / Q000009:adverse effects; D011446:Prospective Studies; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014283:Triiodobenzoic Acids / Q000009:adverse effects
D000891:Anti-Infective Agents, Local; D003287:Contrast Media; D014283:Triiodobenzoic Acids; D011206:Povidone-Iodine; D013972:Thyrotropin; D007455:Iodine; C054871:ioversol; D013974:Thyroxine